Patent survives anticipation attack based on use in phase III clinical trial

6 minute read
22 September 2016


On September 7, 2016, the Federal Court found that Apotex and Cobalt infringed three claims of Bayer's Canadian Letters Patent No. 2,382,426.[1] The Court also found those claims to be valid. The Court reached these conclusions in the context of consolidated patent infringement actions in connection with generic copies of Bayer's Yasmin and Yaz contraceptive products. These parties had previously been involved in related NOC litigation involving these products which ultimately resulted in Cobalt receiving regulatory approval for a generic Yasmin product and Apotex receiving approval for both products.[2]

Clinical Trials did not Anticipate Patent

The Court's analysis of the validity attacks on the 426 Patent on the basis of anticipation may be of particular interest to pharmaceutical innovators. Apotex had alleged that the claims in issue were anticipated based on Phase III clinical trials conducted by Bayer in Europe and the United States more than one year before the 426 Patent was filed in Canada. The Court, however, rejected this allegation.

First, the Court acknowledged that there was a theoretical possibility that one of the tablets had made its way to a public person who was skilled in that art. In particular, no restrictions were imposed on participants in the clinical study regarding disclosure of information concerning the tablets. In addition, while participants were asked to ingest all of the tablets they were provided or return any unused tablets, the evidence established that hundreds of tablets were recorded as lost or not returned during the clinical trials.

Nonetheless, the Court was not persuaded that access to a tablet would have been sufficient to reverse engineer the invention of the 426 Patent. Specifically, the Court found that certain central aspects of the invention (ie. rapid dissolution and the location of the exposure of the pharmaceutically active ingredient) could not have been discovered without inventive insight. In particular, such discovery could not occur without access to several tablets, the ability to obtain a reference standard through the synthesis of the active ingredient and the establishment of a dissolution profile. The skilled person would also have required knowledge of the importance of the location and speed of dissolution. The Court found that the skilled person would not have been able to gather such information without inventive insight. As a result, there was no anticipatory disclosure of the invention claimed in the 426 Patent.

Second, the Court followed jurisprudence permitting an inventor to use any means of testing available to him or her, so long as such experimentation is reasonable and necessary, and done in good faith for the purpose of perfecting the invention or testing its merits. This experimental use exception had also been described as applying in particular, where, of necessity, the experiment must be conducted in public.

The Court found that Bayer's Phase III clinical trial was necessary to evaluate pregnancy prevention in real situations. It thus fell under the experimental use exception. The Court rejected Apotex's argument that the Phase III clinical trial was conducted for the purpose of gaining regulatory approval and, therefore, fell outside the experimental use exception. The Court found that the purpose of a regulatory trial is, in part, to confirm the safety and efficacy of a proposed drug before it is offered for sale to the public. The Court thus held that, while the risks at this advanced stage have been assessed as minimal, this does not detract from the inherently experimental nature of a regulatory trial.

This clarification will be welcome news to pharmaceutical companies who need to conduct clinical trials in support of new (to-be patented) drug candidates. The Court's decision confirms that such trials will not necessarily constitute an anticipatory disclosure, under Canadian patent law, of the invention(s) the drug candidate may embody.

Pharmaceutical companies ought to nonetheless remain vigilant in protecting, through adequate confidentiality agreements and express use restrictions during clinical trials (eg. explicitly specifying drug ingestion and return protocols), their inventions which may be the subject of or accessed through clinical trials. This applies in particular to inventions which could be easily reversed engineered.

Judicial Comity and Stare Decisis have Limited Application Following NOC Proceedings

The Court also had to consider to what extent the decisions in the related NOC litigation were binding on it, whether due to judicial comity or stare decisis.

After acknowledging that the law on this point is not entirely settled, the Court found that the evidentiary context of actions is markedly different than of NOC proceedings. As such, the doctrines of comity and stare decisis have limited application. Specifically, the Court held that the latter applies only to questions of law. In this case, stare decisis was thus only relevant to the question of claim construction. The Court thus considered the Federal Court of Appeal's prior construction to be prima facie binding, though it could have been revisited if warranted by the evidence.

In contrast to the previous findings regarding claim construction, the Court held that previous findings of fact or mixed fact and law made in the NOC context, while potentially persuasive, must be approached with caution. The doctrine of comity thus did not apply to determinations of, in this case, the person of ordinary skill in the art and findings of obviousness.

[1] 2016 FC 1013 [Decision]
[2] See Bayer Inc v Cobalt Pharmaceuticals Company, 2013 FC 1061, aff'd 2015 FCA 116 and Bayer Inc v Apotex Inc, 2014 FC 436.

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